Hello,
Last night's MTT runs show a fairly consistent segfault on the
trunk (1.4a1r20525) in the MPI_Op_free routine, and shows up
in various tests (including the IBM test suite's collective/op test):
http://www.open-mpi.org/mtt/index.php?do_redir=953

I've not investigated in detail, so it could be a coincidence...
but it sure seems like it was caused by either/both of
these changes to the "op" stuff yesterday: r20521 and/or r20522